RESUMO
BACKGROUND: Freezing of gait (FOG) is a disabling and refractory symptom of advanced Parkinson's disease (PD). Interleaved stimulation (ILS) is a novel paradigm which may benefit axial symptoms of PD. OBJECTIVES: To assess the effect of ILS on FOG in patients unresponsive to conventional subthalamic nucleus (STN) stimulation. METHODS: 19 PD patients receiving subthalamic stimulation and experiencing FOG at both conventional (130-150Hz) and low frequency (60Hz) stimulation were given ILS.The primary outcome measure was the UPDRS part III gait score (item 29) at 3 months after ILS. A subset of patients was tested with the stand-walk-sit (SWS) test, 30 min after ILS. RESULTS: The mean UPDRS part III gait score (baseline: 1.8 ± 0.6) improved at 30 min (1.1 ± 0.8, P = 0.017) and remained improved at 3 months (1.2 ± 0.8, P = 0.048). FOG episodes reduced during SWS test (P = 0.041). CONCLUSIONS: ILS of STN through two adjacent contacts provided significant short-term beneficial effects on FOG.